This is the patch for LLVM proper in my series for adding GNUInstallDirs support in all project.
It supersedes D28234, which tried to do the same thing but hand-rolled without GNUInstallDirs.Additionally:
It also cCreates a new `CACHE PATH` variable, `LLVM_EXAMPLES_INSTALL_DIR`, to control where the examples are installed on analogy with the other variables.
Finally,Convert the following are convertedvariables from `CACHE STRING`s to `CACHE PATH`s:
- `LLVM_INSTALL_SPHINX_HTML_DIR` (and similar variables, it is defined reusable module)
Remove stray tabs in `llvm/CMakeLists.txt`
This patch supersedes D28234, which tried to do the same thing but hand-rolled without GNUInstallDirs.